NEW YORK — The stock market suffered its worst day of the year Friday after a surprisingly weak report about hiring and employment cast a pall of gloom over the U.S. economy. The Dow Jones industrial average plunged 274.88 points.

Traders stampeded into the safety of bonds, pushing the yield on the benchmark 10-year Treasury note to a record low. Fearful investors bought gold, causing the price to spike $50 an ounce, and concern about a global economic slowdown drove the price of oil to its lowest since October.

“The big worry now is that this economic slowdown is widening and accelerating,” said Sam Stovall, chief equity strategist at S&P Capital IQ, a market research firm.

It was the Dow’s steepest one-day drop since November.

The Standard & Poor’s 500 and Nasdaq composite both fell more than 3 percent. The Nasdaq has dropped more than 10 percent since its peak — what traders call a market correction. The S&P 500 is just a point above correction territory.

American employers added just 69,000 jobs in May, the fewest in a year, and the unemployment rate increased to 8.2 percent from 8.1 percent. Economists had forecast a gain of 158,000 jobs.

The report, considered the most important economic indicator each month, also said that hiring in March and April was considerably weaker than originally thought. It showed gains in health care, transportation and warehousing, and wholesale trade, while construction jobs fell by a seasonally adjusted 28,000. Even some bright spots, like booming auto sales, failed to bolster manufacturing employment by much — it was up by 12,000 jobs. Once again, government at all levels shed workers.

The jobs report is based on two surveys, one of businesses and the other of households.

But David Rosenberg, the chief economist with Gluskin Sheff, an investment firm, said virtually all of the gain was in part-time work, while the number of full-time workers fell.

“Even the good news in this report was bad,” he said.

The Dow closed down 274.88 points, or 2.2 percent, at 12,118.57. The Dow is off 0.8 percent for the year; two months ago, it was up more than 8 percent for the year.

The S&P 500 fell 32.29 points, or 2.5 percent, to 1,278.04. The Nasdaq dropped 79.86, or 2.8 percent, to 2,747.48. Both indexes are still up for the year — 1.6 percent for the S&P 500 and 5.5 percent for the Nasdaq.

May was the worst month for the stock market in two years by some measures. Investors’ worries about Europe’s debt crisis intensified as the month wore on. Greece’s political future is uncertain, and it appears increasingly likely to stop using the euro currency. That could rattle financial markets and make Greece’s economy — already hobbled — even weaker.

Friday’s jobs report drew traders’ attention back to the weakening U.S. economy, said Todd Salamone, director of research for Schaeffer’s Investment Research in Cincinnati.